Saturday, August 11, 2007

Pawn Races

All positions are White to move unless otherwise noted.

1. Smerdon-Humphrey, Penrith 2003

Counting tells you White queens, then Black queens. If you imagine a White queen on h8 and a Black queen on b1, you'll see Black queens with check, but she can't skewer White's king, so the position's drawn.

But--that evaluation's all wrong! White's king is inside the square of the Black pawn, so instead he captures it and wins. 52.Ke4 Ke2 53.Kd4 Kd2 54.Kc5 1-0.Lesson: Consider "the square of the pawn" before counting.

2. Leick, 1948

At first this looks like the opposite case. White is outside the square of the Black pawn. Black is inside the square of the White pawn.

Black is 3 tempos away from queening (e3-e2-e1). White must queen about the same time to have any chance of drawing. 1.d5! e3 2.dxc6 e2 3.d7 e1=Q 4.d8=Q =. Wrong is 1.Kxc5 e3 2.Kc7 e2 3.c6 e1=Q -/+.

Lesson: In a close pawn race, every tempo counts.

4. Vusatiuk-Panchenko, Kiev 2003

It would take White 6 tempi to promote his h-pawn, but Black only 3 tempi to promote his c-pawn. An immediate race is not in White's best interest.

1.bxc4 bxc4. White is still 6 tempi away, but now Black is 5 tempi away. In addition, White has the first move and will queen with check, so he's well-prepared for the resulting pawn race. 2.Kf6 Kc2 3.Kg7 Kxb2 4.Kxh7 c3 5.Kg6 Kb1 6.h7 c2 7.h8=Q c1=Q =.Lesson: Visualize the result before you enter a pawn race.5. Shishkin-Kislinksy, Kiev 2003

White is 5 tempi from promoting, has the move, and his queening square happens to check the Black king. Black is 6 tempi from promoting--obviously, a pawn race is not in Black's best interests. But he has a trick up his sleeve!

1.d4 Kb6 2.Ke6 Kc7 3.Ke7 Kc6 4.Ke6 Kc7 =

6. Ljaksa-Domuls, USSR 1974

With Black to move, counting would indicate the position is drawn. Both sides are 5 tempi away from promoting and neither side queens with check.

Lesson: Watch for king moves that force your opponent to move his king.

7. Van Scheltinga-Cortlever, Beverwijk 1946

This is the first endgame of this bunch that I got wrong. Van Scheltinga and Cortlever played it accurately! No wonder they scored first and second place, respectively, in the 1947 Beverwijk chess tournament.

No single variation is tricky, but every turn White has to calculate anew whether to shoulder out the black king, gobble up the black pawn, or simply race his pawn towards promotion.

Lesson: In pawn endgames, calculate each move carefully. Sometimes there's no option but to calculate all the variations.

8. Colle-Gruenfeld, Carlsbad 1929

This position is deceptively simple, like pawn endings in general. White races to promote his g-pawn and Black races to promote his f-pawn. King maneuvers seem unlikely since the black king is outside the square of White's g-pawn, and Black's king is able to protect his f-pawn.

1.g6 f4+. The only possible escape squares are h3, h2, g2. Kh3 would allow f1=Q+, so it's a bad idea. Kg2 allows g2+, so it also looks bad. 2.Kh2 f3 3.g7 f2 4.g8=Q f1=Q =. There are no skewers or queen exchanges, and with rook pawns the position is clearly drawish.

Then I checked my notes. Colle won this position?! 2.Kh2? was a mistake, and only 2.Kg2! wins. The trick is, after 2.Kg2 Black must play 2...Ke2 to prevent 3.Kf1. The line plays out 2.Kg2! Ke2 3.g7 f3+ 4.Kg3! f2 5.g8=Q f1=Q +/-. White can force a queen exchange and then win the resulting pawn endgame!

Lesson: Always watch for king moves that force your opponent to move his king!! Even if the enemy thwarts them, his king may wind up on a bad square.